A Magnetic Field-Based Wearable Respiration Sensor for Real-Time
Monitoring During Pulmonary Rehabilitation
Abstract
Objective: In the context of pulmonary rehabilitation exercise
training, wearable real-time monitoring of respiratory patterns may
represent a valuable tool in increasing accessibility to treatment, as
well as expanding the opportunities of treatment automation and
locomotor-respiratory coupling. This work explores Hall effect sensing,
paired with a permanent magnet, embedded in a chest strap.
Methods: Experimental evaluation was performed considering as
reference the gold-standard of respiratory monitoring, an airflow
transducer, and performance was compared to another wearable device with
analogous usability but with a different working principle - a
piezoelectric sensor, also embedded in a chest strap. A total of 16
healthy participants performed 15 different activities, representative
of pulmonary rehabilitation exercises, simultaneously using the three
devices. Evaluation was performed based on detection of flow reversal
events, as well as fiducials detection latency. Results: The
proposed sensor shows comparable performance to the piezoelectric sensor
with a mean ratio, precision, and recall of 1.10, 0.89, and 0.98,
respectively, against 1.35, 0.71, and 0.96 of the piezoelectric sensor,
overall also presenting consistently smaller latencies.
Conclusion: The characterization of the proposed sensor also
shows adequate monitoring capabilities for exercises that do not rely
heavily on torso mobility, but may present a limitation when it comes to
activities such as torso rotations and side stretches.
Significance: This work expands the applicability of Hall effect
sensors, demonstrating their use in the context of real-time respiratory
monitoring.